In the recent years, it is desired to change resin binder raw materials for a toner for electrostatic image development to raw materials derived from natural materials, from the viewpoint of reducing environmental burdens.
For example, a toner that contains a resin binder containing a polyester having a softening point of 80° C. or higher and lower than 120° C., obtained by polycondensing an alcohol component containing 1,2-propanediol in an amount of 65% by mol or more of the divalent alcohol component, and a carboxylic acid component containing a purified rosin, has excellent low-temperature fixing ability, storage property and filming resistance, and also reduces the generation of odors, as disclosed in Japanese Patent Laid-Open No. 2007-139813.
In addition, a toner that contains a resin binder containing a polyester (A) having a softening point of from 120° to 160° C. and a polyester (B) having a softening point of 80° C. or higher and lower than 120° C., wherein the polyester (B) is a polyester obtained by polycondensing an alcohol component and a carboxylic acid component containing a purified rosin, has excellent low-temperature fixing ability, storage property and pulverizability, as disclosed in Japanese Patent Laid-Open No. 2007-139812.
A toner composition using as a binder a nonlinear crosslinked polyester resin of which alcohol component contains a dihydric alcohol, and an acid component contains a rosin, an unsaturated dicarboxylic acid having 4 to 10 carbon atoms, and other dicarboxylic acids in specified amounts, the nonlinear crosslinked polyester resin having specified softening point, glass transition temperature and tetrahydrofuran-insoluble component in specified ranges, has favorable pulverizability during toner production, and has excellent low-temperature fixing ability, offset resistance, blocking resistance or the like, as disclosed in Japanese Patent Laid-Open No. Hei-4-70765.